Conventionally, deposits are formed on workpieces (e.g., substrates) prior to mounting components by jetting droplets of viscous medium (e.g., solder paste, glue, etc.) onto the workpiece. A conventional jetting system generally includes: a nozzle space for containing a relatively small volume of viscous medium prior to jetting; a jetting nozzle coupled to the nozzle space; an impacting device for impacting and jetting the viscous medium from the nozzle space through the jetting nozzle in the form of droplets; and a feeder to feed the medium into the nozzle space.
FIG. 1 illustrates an example of a conventional machine 1 to jet droplets of a viscous medium onto a workpiece 2.
Referring to FIG. 1, the machine 1 includes an X-beam 3 and an X-wagon 4 connected to the X-beam 3 via an X-rail 16 and reciprocally movable along the X-rail 16. The X-beam 3 is reciprocally and movably connected to a Y-rail 17, thereby being movable in directions perpendicular to the X-rail 16. The Y-rail 17 is rigidly mounted in the machine 1. Movement of the X-wagon 4 and the X-beam 3 may be driven by linear motors (not shown).
A conveyer 18 feeds the workpiece 2 through the jetting machine 1. When the workpiece 2 is in the appropriate position under the X-wagon 4, a locking device 19 fixes the workpiece 2 in place. A camera 7 locates fiducial markers on the surface of the workpiece 2 to determine the precise position of the workpiece 2. Viscous medium is applied to the workpiece 2 at desired locations by moving the X-wagon 4 over the workpiece 2 in a given, desired or predetermined pattern and operating a jetting assembly 5 at given, desired or predetermined locations.
The machine 1 also includes an exchange assembly support 20 supporting further assemblies 22, and a vacuum ejector 6.
Since production speed is a relatively important factor in the manufacturing of electronic circuit boards, the application of viscous medium is typically performed “on the fly”. Unfortunately, with conventional technology such as the jetting system shown in FIG. 1, production speed is somewhat limited.